1. Field of the Invention
This invention relates to terpolymers of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and a non-linear, unsaturated hydrocarbon, and, more particularly, to terpolymers of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and isobutylene, within defined compositional ranges, which are useful hydrophilic and hydrophobic terpolymers for application in denture and other adhesives, and as waterproofing agents, and to crosslinked products of such terpolymers, useful as thickeners and stabilizers.
2. Description of the Prior Art
Copolymers of maleic anhydride and alkyl vinyl ethers are well known in the art and are conventionally prepared by free radical precipitation polymerization of the monomer mixture in an aromatic hydrocarbon solvent such as benzene in the presence of a protective colloid. Another method involves copolymerization of maleic anhydride, an alkyl vinyl ether and/or a C.sub.3 -C.sub.10 alkene in contact with a powder bed. In the latter method, disclosed in U.S. Pat. No. 4,370,454, a large excess of the alkyl vinyl ether and/or alkene, e.g. 3 to 25 moles, preferably 5 to 15 moles thereof, per mole of maleic anhydride monomer, is present during the polymerization, instead of the usual 1:1 mole ratio required of the copolymer. In the powder bed method, the heat generated during polymerization is removed by evaporating the excess alkyl vinyl ether and/or alkene which boils at a lower temperature than maleic anhydride. The examples in this patent were directed only to copolymers of maleic anhydride and alkyl vinyl ethers, or copolymers of maleic anhydride and alkene.
Accordingly, an object of the present invention is to provide terpolymers of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and isobutylene, within defined compositional ranges, predetermined for use in various applications, and by a conventional method of preparation.
Still another object herein is to provide hydrophilic terpolymers of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and isobutylene, and a process for making the same, which compositions are useful as adhesives, particularly denture adhesives.
Yet another object is to provide a hydrophobic terpolymer of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and isobutylene, which compositions are useful as waterproofing agents.
Another object of this invention is to provide a benzene-free process for making terpolymers of maleic anhydride, a C.sub.1 -C.sub.5 alkyl vinyl ether and isobutylene of predetermined composition.
Still another object is to provide crosslinked products of the terpolymer of the invention, useful as thickeners and stabilizers.
These and other objects and features of the invention will be made apparent from the following description of the invention.